I'm working on a 03 Lariet F150 with vac. controlled 4x4 (I'm new to this one). Transfer case works, ft drive shaft turns, but the front axle wont engauge. The servo works, and the linkage is tight on the shaft, and the shaft turns back and forth, and the ft axle can be engauge manually by working the small lever back and forth with the servo disconnected, but when zip-tied in place it doesnt stay in 4x4, so something is broken, worn out, or disconnected inside the housing.

Also I repositioned the servo back a bit with a spacer to make sure it wasn't a length of travel issue, and is not - the problem is definately inside - the linkage feels sloppy when manipulated with the servo off.

Since Ive never had one of these apart I thought Id ask first (also a new thing for me), so I'd know what parts to get (I dont live "in town"), and I figger this isn't the first one of these to break. So Im sitting down - what am I in for??? It looks pretty straight forward, but somehow I doubt it is...

Thanks,

Rich

 

Well I sure hope I haven't stumpped the panel on this one.....

I'm also curious about why they went to this system. It's a bit like the posi shift linkage in the rear end of my 78 Case 480 but vacuum operated. Seems primative to me and also not very user servicable - maybe that was the point.

FWIW, I'll take manual hubs any day. I like push button 4x4 (orig equip on my 95 Eddie B. Bronco) for when Im feeling lazy, in a hurry, or in nasty weather, but nothing beats the depndability of manual hubs. I broke two of the auto-locking hubs on the Bronco so when I converted it to the Detroit Tru-trac, I also convereted to manual hubs, giving up push button 4x4 in exchange for reliability.

I've had the stock manual lockng hubs on my 95 since new, broken the IFS mounts, tore a hole in the monster front crossmember, broken a front spring shackle, and broken the right side axle, but never had a problem with the hubs, so Id say the stock Ford units are every bit as good as Warn premiums. I even used them when I converted to the Dana 60. If I can break em, they are as close to bullet proof as you can get!

 

Well this is just wierd - nobody knows about this system and whaa's involved in the repair? Thats a first! Stumped the panel...

 

Alta,,It sounds like you probobly have to pull the front diff cover off, to inspect the shift fork in there,, and see what has come apart ! We just purchased a 01 F-150 2 days ago w/4x4 troubles, so I am just learning about this system too.

I too have made several New posts on this forum,,about the F-150 4x4 system,and No one answered it,,,Being frustrated with no posts, I looked through 40 pages on here and think I may have found the info I need. I tried the "search" feature and it did not help much.

I too like the manual hubs and T-case better,,thats the way my 06' F-350 is equipped.

This 01' F-150 has the manual shift T-case,,which is better,(I think),but still has the vacum front diff actuator,,thats not working at this point,,I think today we can figure it out ! Good Luck with your truck !

is a great site for us FORD TRUCK owners,,and most of the time is very helpful,,I found what I needed for the F-150 ! Later,,,,,Mark

 

Sorry you haven't gotten any help with this. I haven't been here much in the last week, too many irons in the fire.
1) If you can engage/disengage the axle by manually moving the shift fork lever then your issue is with the vacuum system. Check the vacuum on both lines (blue & pink) while putting in/out of 4x4. Remember, the lines must have constant vacuum on them to keep the vacuum diaphragm on the axle engaged in whatever position you have chose. Say for example you engage the axle manually but the 4WD solenoid has a leak, it will disengage itself because there's no vacuum to hold it in.
2) After re-reading your first post I'm seeing that you've zip tied the axle shift fork lever in place in 4WD and it still disengages itself???? I haven't been inside one of these but I don't see how it could do that. I'd think the fork either worked or not. Maybe these will help you see what's in there.


Item Part Number Description
1 3A381 Axle shaft (LH)
2 N808765-S Snap ring
3 3C202 Differential carrier assy
4 3A443 Bushing (2 req'd)
5 373098 Fill plug
6 3N136 Differential housing cover
7 390919 Differential housing cover bolt (10 req'd)
8 390943 Magnetic drain plug
9 F4AZ-19562-B Gasket (silicone)
10 7G360 Front axle actuator motor assy
11 3A380 Axle shaft (RH)
12 3A379 Axle shaft dust deflector
13 3B112 Axle shaft dust seal
14 4B413 Axle shaft bearing assy (outer)
15 3B210 Axle housing tube (RH)
16 4338 Axle housing vent
17 N808703 Axle housing tube bolt
(4 req'd)
18 4121 Identification tag
19 4B413 Axle shaft bearing assy (inner)
20 3N126 Thrust washer (3 req'd)
21 3A392 Axle clutch gear
22 N808704-S E-ring
23 7W082 Clutch shaft rod boot
24 — Shift lever retaining pin
(part of 7K336)
25 7K336 Shift lever




Item Part Number Description
1 389546 Pinion nut
2 4858 Axle universal joint flange
3 4859 Drive pinion oil seal deflector
4 3N134 Pinion seal
5 386989 Slinger
6 4621 Pinion bearing (outer)
7 4662 Drive pinion collapsible spacer
8 3A443 Bushing
9 4616 Pinion bearing cup
10 3A412 Differential carrier
11 3B112 Driveshaft inner dust seal
12 4B413 Axle shaft bearing assy
13 3N139 Clutch fork
14 7R262 Coupler shift selector gear
15 7L253 Axle cluster gear shaft
16 3N106 Pilot bearing assy
17 7G100 Manual shaft retaining pin
18 3C211 Axle shaft shift lever
19 4631 Pinion bearing oil baffle
20 4628 Pinion bearing cup
21 4630 Pinion bearing (inner)
22 4663 Drive pinion bearing adjustment shim
23 3N175 Pinion gear
24 4A451 Differential bearing shim
(2 req'd)
25 4221 Differential bearing cup
(2 req'd)
26 4221 Differential bearing (2 req'd)
27 3A397 Ring gear
28 4205 Differential case
29 388056 Ring gear bolt (10 req'd)
30 387426 Differential pinion shaft bolt
31 4230 Differential pinion thrust washer (2 req'd)
32 4215 Differential pinion gear
(2 req'd)
33 4211 Differential pinion shaft
34 4236 Differential side gear (2 req'd)
35 386984 Differential side gear thrust washer (2 req'd)
36 4224 Differential bearing cap
(2 req'd)
37 391583 Differential bearing cap bolt
(4 req'd)

 

hello i have a 2000 f150 7700 4wd w/ the vac system and thought that i might have to replace the vac unit but all my problem was that the rod for the plunger need to be greased up for more travel. if not used for a while (just a month) and it would start to freeze up. as for the slopyness i presume your talking about the 4/wd lever in the truck. could be a bushing broken cant buy just the bushing you have to buy a kit from ford appx $100.00 hope this helps

 

ncranchero, your schematics of the vacum system, with the solenoids for the F-150 4x4 is very informative, I searched almost all day yesterday,,40 pages,,saw many post's by you and others with some good pics and explanations of the system's, Thanks to all!

 

Okay, read a ton of posts on many different forums. I wish I had read more before starting the 4wd not engaging.

1. Some said it was the transfer case motor--I bought and replaced. I heard
clicking and had a light so I should have left that alone
2. I took off actuator and replaced--it moved freely so should have left that
too
3. The fork arm doesnt move that far
4. I am also a dork as I should have done a few other things before spending
$200 dollars on parts that arent the issue. However, I am keeping them
in since my transfer case motor was rusted bad, the actuator was in
pretty good condition until I popped it out.

So, do I look at selonoids again and vacuum hoses? Or is it in the forks which I will have a transmission house look at?

bummer as I wanted to do this myself. 1999 F150 with 210000 and the kids all use it. I need to use 4wd more often though from what I have been reading.

 

It's been about 2 years since I got my Sport Trac and sold my F150 so I'm going on memory here. The vacuum actuator doesn't move the fork arm very far. I can't remember the stroke on the actuator but if you have the old one you can see it's not much. You have verified vacuum through the lines to the actuator, both of them? You have vacuum out of the solenoids as outlined above? Must always have vacuum on one or the other solenoid. You can manipulate the vacuum lines to where you leave the black & white supply lines (the cut lines in the photo) attached to the solenoids but have the blue & red lines unplugged to verify vacuum is coming through the activated solenoid.

 

Great Picture--okay, if I start the truck and pull the pink hose off while in the 2wd mode I should feel a suction? Same for blue. Do those hoses come off easily and separately? It appears the rubber holds both of them together on mine. I tried and almost pulled the brackett off.

However, if I have my wife turn the switch to 2 and 4 wheel drive and see the actuator move back and forth isnt that telling me I have vacuum on both?

thanks for the pictures and reply. Now I am in the "want to fix it myself mode" before I give in and take it to a mechanic.

 

Exactly

The hoses are on a Siamesed rubber connection but you can remove it and work the pink/blue line to the side of the solenoid. Don't pull the lines out of the rubber, pull the rubber off of the solenoid.



Yes ....... sort of. If there's only vacuum on one line, when the no-vacuum solenoid is selected it will "drift" between 2wd & 4wd. That's why you need to verify there is vacuum on both solenoids when selected.

You also should be sure to call her sweetie/beautiful/sexy before crawling under the truck with her in the drivers seat...truck running and in gear!

You can at least narrow it down to vacuum or mechanical (the blasted fork).

 

I have vacuum on both lines at teh solenoids and at the new actuator. However, no movement of the actuator. Must be the selonoids?? How do you test these for current/resistance? I will probably just replace them. If not the solution, then it goes to the shop as it must be the lever? If actuator not on, how far should fork travel from center plumb back and forth?

 

If you have vacuum at the actuator, one line at a time as you select 4x2/4x4 then the solenoids are good, and you said earlier that you replaced the actuator. Sounds like the internal fork is the problem. Complete stroke of the actuator is maybe an inch IIRC.

PM me your email address and I'll send you some info this afternoon.

 

Went out today, jacked her back up and pulled my new actuator. I moved the fork lever to engage disengage and moved tires verifying no issue with fork lever thank God! I then took hoses off new actuator and sucked both openings to verify the thing moved in/out--it did! I then took the pink line and switched from one side to the other on the actuator to see which line didnt work while I was under truck and the engine running (had a 3 ton jack and 2 jacks under frame just in case) I found the line not working and then took battery out and removed the solenoid that I figured was the issue. I found the body to be cracked from water. I then went to both Autozone and Advanced Auto--neither one had the solenoid. I googled to find this:


Ford has been having chronic problems with water entry into these solenoids, corroding them from the inside and seizing them,as you've seen!

They've been redesigned and those old part numbers (E8AE-9H465-AA/BA) have been superseded.

The latest designs are listed as:
6L3Z-9H465-A (identified by electrical connector rib at 9:00 position)
6L3Z-9H465-B (connector rib at 6:00 position).

Now I have to find -A somewhere to replace. I will have a new transfer case motor, new actuator, and one solenoid. I probably should buy 2. Any good ideas where to get these parts since local auto stores carry something that wont fit this truck.

No snow yet, so have a little time

 

Dealer items, local or online. Glad you've isolated the problem. Got mine at a salvage yard, off of an Expedition. never had any more problems with them as long as I had the truck.